Acidic gas separation laminate and acidic gas separation module provided with laminate

ABSTRACT

An acidic gas separation laminate includes a composite film formed of a porous support which is formed by laminating a porous film and an auxiliary support film and an acidic gas separation facilitated transport film which is disposed on the porous film side of the porous support; a permeating gas channel member which is laminated so as to face the auxiliary support film of the porous support and in which acidic gas permeated and passed through the acidic gas separation facilitated transport film flows; and a film protection unit in which an adhesive becomes impregnated into the porous film at an impregnation rate of 10% or greater in the lamination direction of the porous support and the impregnation rate of the adhesive in the auxiliary support film is smaller than the impregnation rate of the adhesive in the porous film.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation of PCT InternationalApplication No. PCT/JP2014/003989 filed on Jul. 30, 2014, which claimspriority under 35 U.S.C. §119(a) to Japanese Patent Application No.2013-157550 filed on Jul. 30, 2013 and Japanese Patent Application No.2014-151934 filed on Jul. 25, 2014. Each of the above applications ishereby expressly incorporated by reference, in its entirety, into thepresent application.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an acidic gas separation laminatehaving an acidic gas separation function and an acidic gas separationmodule including the laminate.

2. Description of the Related Art

In recent years, a technique of selectively separating out acidic gas inmixed gas has been developed. For example, an acidic gas separationmodule that separates acidic gas from raw material gas using an acidicgas separation film which allow selective permeation of the acidic gashas been developed.

Separation films are roughly classified into so-called facilitatedtransport films in which acidic gas is transported to the opposite sideof the film by a carrier in the separation film and so-calleddissolution diffusion films which performs separation using a differencein solubility of acidic gas and a substance to be separated therefrom ina film and diffusibility in a film.

As a separation film module including such a separation film, filmmodules having various forms such as a spiral type, a flat film type,and a hollow fiber type are used. For example, JP1999-226366A(JP-H11-226366A) discloses a spiral type film module in which aseparation film, a supply side channel member and a permeation sidechannel member are wound around a center pipe and JP1999-216341A(JP-H11-216341A) discloses a flat film type film module.

The spiral type film module is produced by alternately laminating aleaf, in which a supply side channel member is arranged between filmsobtained by folding a separation film into two, with a permeation sidechannel member, coating the three sides of a laminate peripheralportion, which is formed of the separation film and the permeation sidechannel member, with an adhesive to prepare a separation film unit so asto prevent a supply side fluid and a permeation side fluid from beingmixed with each other; winding one or a plurality of the separation filmunits around a center pipe (fluid collecting pipe) in the form of aspiral, and trimming (end surface modifying process) end portions of anobtained cylindrical wound body.

The film type module is obtained by arranging a separation film on onesurface or both surfaces of a permeation side channel member, alsocoating three sides of the laminate peripheral portion with an adhesiveto prepare a separation film unit, and bonding one side which is notcoated with the adhesive to a fluid collecting pipe.

In both modules, a sealing unit formed by an adhesive is extremelyimportant from a viewpoint of preventing a supply side fluid and apermeation side fluid from being mixed with each other to increaseseparation performance.

Since the sealing performance is degraded when sealing precisionresulting from the sealing unit is not sufficient, a sealing method withhigh precision and a filling rate or an adhesion width of an adhesivehave been examined several times (JP2009-18239A, JP1991-68428A(JP-H03-68428A), and the like).

SUMMARY OF THE INVENTION

In a case where a substance to be separated is a gas, since gas leaksmore frequently than a liquid at the time of an operation and acidic gasis separated from raw material gas containing water vapor in an acidicgas separation module which includes a facilitated transport film, theviscosity of a separation film (facilitated transport film) isdecreased. Further, the pressure of the supply gas is greater than orequal to atmospheric pressure and thus a difference in pressure isgenerated between the supply gas side and the permeating gas side. Then,a difference in pressure is applied to the separation film whoseviscosity is decreased. Further, since a sealing unit in which pores arefilled with an adhesive and portions other than the sealing unit havemechanical strengths different from each other when the difference inpressure is applied, stress concentration is likely to occur inboundaries therebetween. Due to great stress being applied to theboundaries, defects are generated in the separation film.

In addition, as described above, in a case of a spiral type module, aleaf in which a supply fluid channel member is interposed between theseparation film folded into two is used, but the folded portion of theseparation film folded into two may be damaged (defects may begenerated) in some cases.

Defects in the separation film allow a supply fluid and a permeatingfluid to be mixed with each other and becomes a factor of degradation ofseparation performance.

An object of the present invention is to provide an acidic gasseparation laminate which is capable of suppressing generation ofdefects in a separation film and is applied to an acidic gas separationmodule and to provide an acidic gas separation module which includes thelaminate.

According to an aspect of the present invention, there is provided anacidic gas separation laminate including: a composite film formed of aporous support which is formed by laminating a porous film and anauxiliary support film, a carrier which is disposed on the porous filmside of the porous support and reacts with acidic gas in raw materialgas, and an acidic gas separation facilitated transport film whichcontains a hydrophilic compound carrying the carrier; a permeating gaschannel member which is laminated so as to face the auxiliary supportfilm of the porous support and in which acidic gas having permeated andpassed though the acidic gas separation facilitated transport filmflows; and a film protection unit in which an adhesive becomesimpregnated into the porous film at an impregnation rate of 10% orgreater in the lamination direction of the porous support and theimpregnation rate of the adhesive in the auxiliary support film issmaller than the impregnation rate of the adhesive in the porous film.

Here, the “impregnation rate of an adhesive” indicates the filling rateof the adhesive with respect to gaps (pores) in each of the porous film,the auxiliary support film, and the gas channel member.

The impregnation rate of the adhesive is obtained by performing threefield (three sections are cut out and one film protection unit for onesection is observed) observation on the section on which the filmprotection unit of the laminate is formed after the adhesive is appliedusing a scanning electron microscope (SEM) or an optical microscope andacquiring the ratio of the area of the adhesive filled into pores to thearea of pores of each film and members by carrying out image processingafter the adhesive is applied.

It is preferable that the acidic gas separation laminate furtherincludes a sealing unit which is formed by impregnating the porous filmwith the adhesive along the peripheral edge of the laminate at animpregnation rate of 60% or greater and impregnating the auxiliarysupport film and the permeating gas channel member with the adhesivesuch that the respective impregnation rates become greater than or equalto the impregnation rate of the adhesive in the porous film and the filmprotection unit is formed in a state of being adjacent to the sealingunit.

Here, the impregnation rate of the adhesive is acquired from the fillingarea of the adhesive with respect to the area of pores in the respectiveunits of the porous film, the auxiliary support film, and the permeatinggas channel member from the end portion of the laminate for each widthof 0.01 mm, and a region in which the impregnation rate of the adhesivein the porous film is 60% or greater and in which the impregnation rateof the adhesive in the auxiliary support film is greater than thepermeation rate of the porous film is specified as a sealing unit.

In the sealing unit, it is preferable that the impregnation rate of theadhesive in the auxiliary support film and the gas channel member is 80%or greater.

Further, the sealing unit does not need to be provided in the entireperipheral edge of the laminate and may be provided in the portion whichneeds to be sealed in the peripheral edge. Moreover, the width of thesealing unit may be non-uniform in the surface direction of thelaminate, but it is desired that the width thereof be 5 mm or greater atall places.

It is preferable that the acidic gas separation laminate furtherincludes a supply gas channel member which is disposed between theacidic gas separation facilitated transport films of the composite filmthat is obtained by inwardly folding the acidic gas separationfacilitated transport film into two in the length direction, in whichthe film protection unit is formed on a portion overlapping the acidicgas separation facilitated transport film portion with which an endportion of the supply gas channel member is brought into contact, thatis, on the folded portion of the composite film folded into two.

It is preferable that the porous film is formed of a fluorine-basedresin material.

It is preferable that the porous film is formed ofpolytetrafluoroethylene.

It is preferable that the adhesive is formed of an epoxy resin.

It is preferable that the acidic gas separation laminate of the presentinvention further includes an intermediate layer between the porous filmand the acidic gas separation facilitated transport film.

It is preferable that the intermediate layer is a silicone resin layer.

According to another aspect of the present invention, there is providedan acidic gas separation module including a permeating gas collectingpipe; and the acidic gas separation laminate of the present invention,in which the permeating gas channel member other than where the sealingunit of the acidic gas separation laminate is not formed is connected tothe permeating gas collecting pipe.

The acidic gas separation module of the present invention may be aspiral type module or a flat film type module.

Since the acidic gas separation laminate of the present inventionincludes a film protection unit which is formed by an adhesivepermeating into the porous film in contact with the facilitatedtransport film, a portion in which stress concentration occurs so thatdefects are easily generated in the facilitated transport film isprotected and the generation of defects is suppressed, permeation ofsupply gas can be suppressed in a case where defects are generated whenthe acidic gas separation laminate is incorporated in the acidic gasseparation module and used, and thus degradation of separationperformance of a module can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view schematically illustrating an acidic gasseparation laminate according to an embodiment of the present invention.

FIG. 1B is a view for describing effects of the acidic gas separationlaminate of the present invention.

FIG. 1C is a view illustrating an example of the shape of a sealing unitof the acidic gas separation laminate of the present invention.

FIG. 1D is a view illustrating an example of the shape of the sealingunit and a stress buffer unit of the acidic gas separation laminate ofthe present invention.

FIG. 1E is a view illustrating a design modification example of theacidic gas separation laminate of the present invention.

FIG. 2A is a partial sectional view illustrating a process of producingthe acidic gas separation laminate.

FIG. 2B is a partial sectional view illustrating the process ofproducing the acidic gas separation laminate, continuing after FIG. 2A.

FIG. 2C is a partial sectional view illustrating the process ofproducing the acidic gas separation laminate, continuing after FIG. 2B.

FIG. 2D is a partial sectional view illustrating the process ofproducing the acidic gas separation laminate, continuing after FIG. 2C.

FIG. 3A is a view illustrating a method of applying an adhesive using aslot die.

FIG. 3B is a view illustrating another method of applying an adhesiveusing a slot die.

FIG. 4A is a plan view illustrating a method of applying an adhesiveusing a stamp.

FIG. 4B is a side view illustrating the method of applying an adhesiveusing a stamp.

FIG. 5 is a configuration view schematically illustrating a spiral typemodule by cutting out a part thereof according to the embodiment of thepresent invention.

FIG. 6 is a view illustrating the state before the laminate is woundaround the permeating gas collecting pipe.

FIG. 7 is a sectional view illustrating a part of a cylindrical woundbody obtained by winding a laminate around a permeating gas collectingpipe.

FIG. 8A is a view illustrating a process of producing the spiral typemodule.

FIG. 8B is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8A.

FIG. 8C is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8B.

FIG. 8D is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8C.

FIG. 8E is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8D.

FIG. 8F is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8E.

FIG. 8G is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8F.

FIG. 8H is a view illustrating the process of producing the spiral typemodule, continuing after FIG. 8G.

FIG. 8I is a sectional view taken along the line 8I-8I of FIG. 8H.

FIG. 9 is a view illustrating the process of producing the spiral typemodule continuing after FIG. 8H.

FIG. 10 is a view illustrating a modification example of the process ofproducing the spiral type module.

FIG. 11 is a perspective view schematically illustrating a flat surfacetype module according to an embodiment of the present invention.

FIG. 12 is a sectional view taken along the line XII-XII of the flatsurface type module illustrated in FIG. 11.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be described withreference to the accompanying drawings. Further, in the drawingsdescribed below, members (constituent elements) having the same orcorresponding functions are denoted by the same reference numerals andthe description thereof is appropriately omitted.

[Acidic Gas Separation Laminate]

FIG. 1A is a perspective view schematically illustrating a laminationconfiguration of an acidic gas separation laminate 1 according to anembodiment of the present invention and FIG. 1B is an enlarged sectionalview of the end portion of the laminate 1.

As illustrated in FIG. 1A, the acidic gas separation laminate 1 of theembodiment includes a gas separation composite film (hereinafter, gasseparation film) 10 formed of a porous support 4 which is formed bylaminating a porous film 2 and an auxiliary support film 3 and an acidgas separation facilitated transport film 5 which is disposed on theporous film 2 side of the porous support 4 and contains a carrierdirectly or indirectly reacting with acidic gas in raw material gas(supply gas) and a hydrophilic compound carrying the carrier, and apermeating gas channel member 6 which is disposed on the auxiliarysupport film 3 side of the porous support 4 and in which acidic gaspermeating through the acid gas separation facilitated transport film 5and the porous support 4 flows.

In addition, there is provided a sealing unit 7 and a film protectionunit 9 in a state of being adjacent to the sealing unit 7 for thepurpose of preventing inflow of gas to the porous support 4 and thepermeating gas channel member 6 on three sides of the peripheral edge(four sides), except one side, of the rectangular laminate 1. The filmprotection unit 9 has a function of preventing generation of defects inthe facilitated transport film 5 and suppressing leakage of supply gasto the permeating gas channel member 6 side in a case where defects aregenerated in the facilitated transport film 5.

The sealing unit 7 is a portion configured by an adhesive 8 having beenimpregnated into the porous support 4 and the channel member 6, and theadhesive 8 becomes impregnated into the porous film 2 of the poroussupport 4 at an impregnation rate of 60% or greater in the laminationdirection and the adhesive 8 becomes impregnated into the auxiliarysupport film 3 and the channel member 6 at an impregnation rate greaterthan or equal to the impregnation rate of the adhesive in the porousfilm 2. It is preferable that a width x of the sealing unit 7(hereinafter, the sealing width x) is 5 mm or greater from the endportion of the laminate 1.

When the sealing unit 7 can be formed over a region from the end portionof the laminate 1 at 5 mm or longer, the sealing function can besufficiently ensured. Meanwhile, since the effective region for gasseparation becomes narrower when the sealing width x becomes longer andthe region of the sealing unit becomes larger, it is preferable that thesealing width x is not extremely long in a case where the sealing widthx is 5 mm or greater. The sealing width x is preferably in a range of 5mm to 70 mm and particularly preferably in a range of 10 mm to 50 mm.

Moreover, since the adhesive does not necessarily spread uniformly, asillustrated in the schematic view of FIG. 1C, the sealing width x of thesealing unit 7 may be different in each portion of the laminate 1 in theplane direction, and the smallest sealing width is preferably 5 mm orgreater. In addition, as described above, a portion in which theimpregnation rate of the adhesive in the porous film 2 from the endportion of the laminate 1 is 60% or greater and the impregnation rate ofthe adhesive in the auxiliary support film 3 and the channel member 6 isgreater than or equal to the impregnation rate of the adhesive in theporous film 2 is specified as a sealing unit, but, as illustrated inFIG. 1D, there may be a portion (adhesive extension portion) whichextends while the impregnation rate of the adhesive from the sealingunit to the inside of the laminate becoming gradually smaller than theimpregnation rate of the adhesive in the sealing unit. In this case, theadhesive extension portion has an insufficient sealing function.Further, it is preferable that the adhesive extension portion is smallbecause it has an adverse effect of inhibiting permeating gastransportation.

Moreover, the width of the film protection unit 9 may be different ineach portion of the laminate in the plane direction similar to thesealing unit. The width of the film protection unit 9 is preferably 20mm or greater and more preferably 40 mm or greater.

The film protection unit 9 surrounded by a dashed line in FIG. 1B is aregion in which the adhesive becomes impregnated into the porous film 2of the porous support 4 at an impregnation rate of 10% or greater andthe impregnation rate of the adhesive in the auxiliary support film 3 issmaller than the impregnation rate of the adhesive in the porous film 2.Further, the impregnation rate of the adhesive in a region in which thepermeating gas channel member 6 is laminated on the film protection unit9 is smaller than the impregnation rate of the adhesive in the porousfilm 2.

In the film protection unit 9, the impregnation rate of the adhesive inthe porous film 2 is preferably 10% or greater, more preferably 40% orgreater, and still more preferably 60% or greater. In addition, theimpregnation rate of the adhesive in the auxiliary support film 3 may besmaller than the impregnation rate of the adhesive in the porous film 2.The impregnation rate thereof is preferably as small as possible, morepreferably less than 60%, still more preferably less than 40%, and evenstill more preferably less than 10%. The same applies to theimpregnation rate of the adhesive in the region in which the permeatinggas channel member 6 is laminated on the film protection unit 9.

In the example, the laminate 1 is rectangular and the sealing unit 7 andthe film protection unit 9 are formed in the three sides of theperipheral edge except one side. Moreover, the shape of the laminate 1and the region in which the sealing unit 7 and the film protection unit9 are formed can be suitably set according to the configuration of amodule to which the laminate is applied.

The laminate 1 is applied to a separation film module that separatesacidic gas from raw material gas (supply gas) containing acidic gas andsuitably used in a case where a supply gas contains water vapor. Whenthe laminate 1 is applied to the separation film module, the viscosityof the facilitated transport film 5 is degraded by absorbing moisture.At this time, the facilitated transport film 5 is pressed to the porousfilm 2 side by a pressure S (differential pressure between the supplygas and the permeating gas) resulting from the supply gas and amechanical strength (rigidity) of a region into which the adhesive ofthe laminate 1 becomes impregnated is different from a mechanicalstrength of a region into which the adhesive thereof has not becomeimpregnated, and thus stress concentration occurs in the boundarybetween both regions and defects may occur in the facilitated transportfilm 5 at the boundary. The laminate 1 which is an embodiment of thepresent invention includes the film protection unit 9 in a state ofbeing adjacent to the sealing unit 7 as illustrated in the enlarged viewof FIG. 1B, and the occurrence of defects in the facilitated transportfilm 5 can be suppressed by the film protection unit 9 functioning as abuffer unit that alleviates stress concentration. When gas separation isperformed by a module, a predetermined pressure S is normally applied tothe facilitated transport film 5 from the supply gas side due to thepressure difference (differential pressure) between the supply gas andthe permeating gas. At this time, since the rigidity of the poroussupport 4 varies due to the impregnation rate (including the presence orabsence of permeation) of the adhesive, stress concentration occurs inthe facilitated transport film 5 at a boundary position between regionswhose rigidities are greatly different from each other, for example, aportion indicated by an arrow P in FIG. 1B. In a case where the filmprotection unit 9 does not exist, since the sealing unit 7 is adjacentto a region into which the adhesive has not become impregnated at all,the stress concentration becomes greater and defects are likely to occurin the facilitated transport film 5. However, since the rigidity can begradually changed when the film protection unit 9 is included, thestress concentration can be alleviated.

Since a certain degree of stress concentration occurs in an interface Pbetween the sealing unit 7 and the film protection unit 9 even when thefilm protection unit 9 is included, cracks are generated in thefacilitated transport film 5 in some cases. However, since the adhesivehas become impregnated into the porous film 2 in the film protectionunit 9, it is possible to suppress passing of supply gas, which haspermeated into the cracks of the facilitated transport film 5, into thepermeating gas channel member 6 side. The effect of suppressingpermeation of the supply gas into the permeating gas channel member sidecan be obtained when the impregnation rate of the adhesive in the porousfilm 2 is 10% or greater, the effect can be increased when theimpregnation rate of the adhesive is 40% or greater, and the effectbecomes significant when the impregnation rate of the adhesive is 60% orgreater. Further, in the auxiliary support film 3 and the permeating gaschannel member 6 of the film protection unit 9, the impregnation rate ofthe adhesive is preferably as small as possible.

Further, as illustrated in FIG. 1D, the impregnation rate of theadhesive is calculated by acquiring the ratio of an area into which theadhesive is filled to an area of pores of respective layers (the porouslayer 2, the auxiliary support film 3, and the channel member 6) throughimage processing for each area having a width of 0.01 mm from the endportion in the section, for example, for each area c_(i) having a widthdefined by dashed lines in FIG. 1D. In addition, the width of thesealing unit and the width of the film protection unit are acquired fromthe impregnation rate of the adhesive. The impregnation rate of theadhesive in the porous film for each region (hereinafter, a measurementunit region) having a width of 0.01 mm from the end portion is acquired,a region from the end portion to the farthest measurement unit region(region c_(n) in FIG. 1D) in the measurement unit region in which aimpregnation rate of the adhesive being 60% or greater in the porousfilm and a condition in which the impregnation rate of the adhesive inthe auxiliary support film and the gas channel member is greater than orequal to the impregnation rate of the adhesive in the porous film aresatisfied is set as the sealing unit 7, and the distance from the endportion of the laminate to an end 7 b on a side distant from thelaminate end portion of the measurement unit region c_(n) is set as thewidth of the sealing unit 7. In addition, a region in which theimpregnation rate in the porous film 2 is 10% or greater and theimpregnation rate of the adhesive in the auxiliary support film 3 issmaller than the impregnation rate of the adhesive in the porous film 2is the film protection unit 9. As illustrated in FIG. 1C, theimpregnation region of the adhesive is greatly different for eachposition at which a sealing unit and the film protection unit are formedin the in-plane direction in many cases, and average values of valuesobtained from plural places (for example, three places) in the sectionare used as the width of the sealing unit and the width of the filmprotection unit.

<Gas Separation Film>

The gas separation film 10 includes the acidic gas separationfacilitated transport film 5 and the porous support 4 which supports thefacilitated transport film 5 and is provided on the side of thepermeating gas channel member 6.

(Acidic Gas Separation Facilitated Transport Film)

The acidic gas separation facilitated transport film 5 contains at leasta carrier directly or indirectly reacting with acidic gas in rawmaterial gas and a hydrophilic compound carrying the carrier, and has afunction of allowing the acidic gas to selectively permeate from the rawmaterial gas.

Since the facilitated transport film 5 normally has more heat resistancethan a dissolution diffusion film, the acidic gas can selectivelypermeate under a temperature condition of, for example, 100° C. to 200°C. Further, even when the raw material gas contains water vapor, ahydrophilic compound absorbs the water vapor such that the facilitatedtransport film containing the hydrophilic compound holds moisture andthus the carrier is easily transported. Therefore, the separationefficiency is increased compared to a case of using a dissolutiondiffusion film.

The film area of the facilitated transport film 5, which is notparticularly limited, is preferably in a range of 0.01 m² to 1000 m²,more preferably in a range of 0.02 m² to 750 m², and still morepreferably in a range of 0.025 m² to 500 m². Further, from a practicalviewpoint, the film area is preferably in a range of 1 m² to 100 m².

When the film area is set to be greater than or equal to each lowerlimit, the acidic gas can be separated out efficiently with respect tothe film area. In addition, when the film area is set to be less than orequal to each upper limit, the workability is improved.

The thickness of the facilitated transport film 5, which is notparticularly limited, is preferably in a range of 1 μM to 200 μm andmore preferably in a range of 2 μm to 175 μm. When the thickness is inthe above-described range, the gas permeability and separationselectivity can be sufficiently realized, which is preferable.

(Hydrophilic Compound)

As the hydrophilic compound, a hydrophilic polymer is exemplified. Thehydrophilic polymer functions as a binder and exhibits a function ofholding water to allow separating out of acidic gas performed by anacidic gas carrier. It is preferable that the hydrophilic compound hashigh hydrophilicity and absorbs water whose mass is 5 times to 1000times the mass of the hydrophilic compound itself from the viewpointthat the hydrophilic compound is capable of forming a coating solutionby being dissolved in water or dispersed in water and an acidic gasseparation layer has high hydrophilicity (moisture retaining property).

From viewpoints of hydrophilicity, film-forming properties, andstrength, as the hydrophilic polymer, polyvinyl alcohol polyacrylate, apolyvinyl alcohol-polyacrylic acid (PVA-PAA) copolymer, polyvinylalcohol, polyacrylic acid, polyacrylate, polyvinyl butyral,poly-N-vinylpyrrolidone, poly-N-vinylacetamide, or polyacrylamide ispreferable and a PVA-PAA copolymer is particularly preferable. A PVA-PAAcopolymer has high water absorption performance and high strength in ahydrogel state at the time of high water absorption. The percentagecontent of polyacrylate in the PVA-PAA copolymer is preferably in arange of 5% by mole to 95% by mole and more preferably in a range of 30%by mole to 70% by mole. Examples of the polyacrylate include alkalimetal salts such as sodium salts or potassium salts, aluminum salts, andorganic ammonium salts.

As a commercially available PVA-PAA copolymer, KURASTOMER AP20(manufactured by KURARAY CO., LTD.) is exemplified.

(Acidic Gas Carrier)

The acidic gas carrier has affinity for acidic gas (for example, carbondioxide) and is various kinds of water-soluble compound showingbasicity. Further, the acidic gas carrier indirectly reacts with acidicgas or the carrier itself directly reacts with acidic gas. Theexpression “the carrier indirectly reacts with acidic gas” indicatesthat, for example, the carrier generates a basic compound by reactingwith another gas contained in a supply gas and then the basic compoundreacts with the acidic gas. As such an acidic gas carrier, specifically,an alkali metal or an alkali metal compound which is capable ofselectively taking CO₂ into a film by being brought into contact withsteam (water vapor) to release OH⁻ and by OH⁻ reacting with CO₂ isexemplified.

Moreover, as the acidic gas carrier directly reacting with acidic gas, anitrogen-containing compound or a sulfur oxide, which has basicity, maybe exemplified.

Regarding alkali metal compounds, an aqueous solution obtained by addinga multidentate ligand forming a complex with an alkali metal ion to anaqueous solution containing at least one selected from a groupconsisting of alkali metal carbonates, alkali metal bicarbonates, andalkali metal hydroxides is exemplified.

In addition, in the specification, an alkali metal or an alkali metalcompound is used with the meaning of including the salts thereof and theions thereof.

Examples of the alkali metal carbonate include lithium carbonate, sodiumcarbonate, potassium carbonate, rubidium carbonate, and cesiumcarbonate. Examples of the alkali metal bicarbonate include lithiumhydrogencarbonate, sodium hydrogencarbonate, potassiumhydrogencarbonate, rubidium hydrogencarbonate, and rubidiumhydrogencarbonate.

Examples of the alkali metal hydroxide include lithium hydroxide, sodiumhydroxide, potassium hydroxide, rubidium hydroxide, and cesiumhydroxide.

Among these, alkali metal carbonates are preferable and a compoundcontaining potassium, rubidium, and cesium, which have high solubilityin water, as alkali metal elements is preferable from a viewpoint thataffinity for acidic gas is excellent.

In the embodiment, since a hygroscopic facilitated transport film isused, a phenomenon (blocking) in which the facilitated transport filmenters a gel state due to the absorbed moisture at the time ofproduction and then the facilitated transport film adheres to anotherfilm or another member at the time of production easily occurs. In acase where blocking occurs, defects occur in the facilitated transportfilm due to the adhesion when the facilitated transport film is peeledoff from another film or another member and, as a result, gas leakagemay occur. Therefore, in the embodiment, it is preferable to attempt toprevent this blocking.

Here, in the embodiment, it is preferable that a carrier contains two ormore kinds of alkali metal compound. When the carrier contains two ormore kinds of alkali metal compound, the same kind of carrier in a filmcan be separated to a distant place so that non-uniformity in blockingis generated and thus the blocking can be prevented.

Moreover, it is more preferable that a carrier contains a first alkalimetal compound having deliquescency and a second alkali metal compoundwhich has lower deliquescency than that of the first alkali metalcompound and which has a low specific gravity. Specifically, cesiumcarbonate may be exemplified as the first alkali metal compound andpotassium carbonate may be exemplified as the second alkali metalcompound.

When a carrier contains the first alkali metal compound and the secondalkali metal compound, the second alkali metal compound having a lowspecific gravity is arranged on the film surface side of the facilitatedtransport film (that is, arranged by being unevenly distributed on thesurface side of the facilitated transport film) and the first alkalimetal compound having a high specific gravity is arranged on the insideof the facilitated transport film (that is, arranged by being unevenlydistributed on the porous support side of the facilitated transportfilm). Further, since the second alkali metal compound arranged on thefilm surface side has lower deliquescency than that of the first alkalimetal compound, the film surface does not become sticky and blocking canbe prevented in contrast to a case where the first alkali metal compoundis arranged on the film surface side. Moreover, since the first alkalimetal compound having high deliquescency is arranged inside of the film,blocking can be prevented and the separation efficiency of carbondioxide gas can be increased in contrast to a case where the secondalkali metal compound is simply arranged in the entire film.

Specifically, in a case where two or more kinds of alkali metalcompounds (first and second alkali metal compounds) are used ascarriers, the facilitated transport film 5 is formed of a second layeron the surface side which is the side opposite to the porous support 4and a first layer on the porous support 4 side as a portion below thesecond layer. In addition, the entire facilitated transport film 5 isconfigured of hydrophilic compounds (hydrophilic polymers), and thesecond layer mainly contains a second alkali metal compound which haslow deliquescency and a low specific gravity, among the compounds.Mainly, a first alkali metal compound having deliquescency is present inthe first layer. In addition, the thickness of the second layer is notparticularly limited, but the thickness thereof is preferably in a rangeof 0.01 μm to 150 μm and more preferably in a range of 0.1 μm to 100 μmfrom a viewpoint of exhibiting a function of sufficiently suppressingdeliquescency.

For example, the second layer containing the second alkali metalcompound is unevenly distributed on the surface side of the facilitatedtransport film 5 and the first layer containing the first alkali metalcompound extends in the lower portion of the second layer, but there isnot limitation thereto. For example, the interface between the twolayers may not be clear and the two layers may be distinguished fromeach other in a state in which the concentrations of the two layerschange in a gradual manner. In addition, the interface therebetween maynot be flat and may be in a state of having moderate undulations.

The deliquescency of a film is suppressed by an action of the secondlayer containing the second alkali metal compound having lowdeliquescency and a low specific gravity. The reason why the secondalkali metal compound is unevenly distributed is that the specificgravity of two or more kinds of alkali metal is different from eachother. That is, by adjusting the specific gravity of one metal fromamong the two or more alkali metals to be low, the metal having a lowspecific gravity can be localized in the upper portion (surface side) ina coating solution at the time of producing a film. In addition,condensation or the like can be prevented on the film surface of thesecond layer using properties of the second alkali metal compound ofeasily being crystallized while high transportation capacity of carbondioxide or the like included in the first alkali metal compound, whichhas deliquescency, contained in the first layer on the inside of thefilm is maintained. In this manner, blocking is prevented and separationefficiency of carbon dioxide can be increased.

Moreover, since the second alkali metal compound may be present only onthe film surface side for the purpose of preventing blocking, it ispreferable that the second alkali metal compound is contained in asmaller amount than the first alkali metal compound. In this manner, theamount of the first alkali metal compound having high deliquescencybecomes relatively large in the entire film and thus the separationefficiency of carbon dioxide can be further increased.

The ratio of the first alkali metal compound to the second alkali metalcompound is not particularly limited, but the content of the firstalkali metal compound is preferably 50 parts by mass or greater and morepreferably 100 parts by mass or greater with respect to 100 parts bymass of the second alkali metal compound. The upper limit thereof ispreferably 100000 parts by mass or less and more preferably 80000 partsby mass or less. By adjusting the ratio of the first alkali metalcompound to the second alkali metal compound to be in theabove-described range, the blocking properties and handling ability canbe established at a high level.

Here, the number of kinds of two or more alkali metal compounds isdetermined by the kind of alkali metal and alkali metal compounds aredetermined not to be counted as one kind when the compounds havecounterions different from each other. In other words, when potassiumcarbonate and potassium hydroxide are combined with each other, acompound having this combination can be counted as one kind of alkalimetal compound.

As a combination of two or more kinds of alkali metal compound, thefollowing combinations listed in Table 1 are preferable. In addition, inTable 1, the alkali metal compounds are displayed by the name of alkalimetals, but salts or ions thereof may be used.

TABLE 1 Second alkali metal First alkali metal Combination compoundcompound No. 1 Potassium Cesium No. 2 Potassium Rubidium No. 3 PotassiumCesium/rubidium

The content of all the acidic gas carriers in the facilitated transportfilm also depends on the ratio of the amount of hydrophilic compounds tothe acidic gas carriers and the kind of acidic gas carrier, but ispreferably in a range of 0.3% by mass to 30% by mass, more preferably ina range of 0.5% by mass to 25% by mass, and particularly preferably in arange of 1% by mass to 20% by mass from viewpoints of preventingsalting-out before application, reliably exhibiting the function ofseparating out acidic gas, and having excellent stability in the usageenvironment.

In a case where two or more kinds of alkali metal compound are used ascarriers, when the content of the two or more kinds of alkali metalcompound is described using a relationship between the content thereofand the total mass of solid contents of a hydrophilic compound which isa main component of a film, two or more kinds of alkali metal compound,and the like, the mass ratio of the two or more kinds of alkali metalcompound is preferably in a range of 25% by mass to 85% by mass and morepreferably in a range of 30% by mass to 80% by mass. When the amountthereof is adjusted to be in the above-described range, the function ofseparating out gas can be sufficiently exhibited.

In regard to the second alkali metal compound (alkali metal compoundwhich is unevenly distributed on the surface side of the facilitatedtransport film 5) having lower deliquescency and a low specific gravitythan the first alkali metal compound among two or more alkali metalcompounds, the content thereof is preferably 0.01% by mass or greaterand more preferably 0.02% by mass or greater with respect to the totalmass of the solid contents such as a hydrophilic compound, two or morekinds of alkali metal compound, and the like. The upper limit thereof,which is not particularly limited, is preferably 10% by mass or less and7.5% by mass or less. When the amount of the second alkali metalcompound is extremely small, the blocking may not be prevented. Inaddition, when the amount thereof is extremely large, handling of thecompound may become difficult.

Examples of the nitrogen-containing compound include ammonia, ammoniumsalts, various linear and cyclic amines, amine salts, and ammoniumsalts. Further, these water-soluble derivatives thereof are preferablyused. Since a carrier which can be held in the facilitated transportfilm for a long period of time is useful, an amine-containing compoundwhich is unlikely to be evaporated, for example, an amino acid orbetaine is particularly preferable. As amine-containing compounds, aminoacids such as glycine, alanine, serine, proline, histidine, taurine, anddiaminopropionic acid; hetero compounds such as pyridine, histidine,piperazine, imidazole, and triazine; alkanolamines such asmonoethanolamine, diethanolamine, triethanolamine, monopropanolamine,dipropanolamine, and tripropanolamine; cyclic polyether amines such ascryptand[2.1] and cryptand[2.2]; bicyclic polyether amines such ascryptand[2.2.1] and cryptand[2.2.2]; porphyrin; phthalocyanine; andethylenediaminetetraacetic acid can be used.

As sulfur compounds, amino acids such as cystine and cysteine;polythiophene; and dodecylthiol can be used.

(Others)

The facilitated transport film may contain other components (additives)other than the hydrophilic polymer, the acidic gas carrier, and waterwithin a range not adversely affecting separation characteristics. Ascomponents which can be arbitrarily used in a process of coating theporous support with an aqueous solution (coating solution) for forming afacilitated transport film containing a hydrophilic polymer and anacidic gas carrier and drying the support, a gelling agent which cools acoating solution film to be gelled and controls so-called settingproperties; a viscosity modifier which adjusts the viscosity at the timeof coating the support with the coating solution using a coating device;a cross-linking agent which is used for improving film strength of thefacilitated transport film; an acidic gas absorption promoting agent, asurfactant, a catalyst, a co-solvent, a film strength control agent, anda detection agent which facilitates inspection for the presence orabsence of detects in a formed facilitated transport film areexemplified.

<Porous Support Film>

The porous support 4 that supports the facilitated transport film 5 isformed by laminating the porous film 2 and the auxiliary support film 3on each other. When the auxiliary support film 3 is included, effectsfor improving mechanical strength and avoiding wrinkles at the time ofhandling with a coating machine can be obtained and productivity can beimproved.

(Porous Film)

The porous film 2 has permeability with respect to acidic gases such ascarbon dioxide or the like, which are separated out.

From a viewpoint of suppressing permeation through a facilitatedtransport material at the time when a facilitated transport film isformed, it is preferable that the porous film 2 has a small porediameter. It is preferable that the maximum pore diameter is 1 μm orless. The lower limit of the pore diameter, which is not particularlylimited, is approximately 0.001 μm.

Here, the maximum pore diameter indicates a value measured andcalculated by a bubble point method. For example, the maximum porediameter can be measured using a perm-porometer (manufactured by PlanarMonolithics Industries, Inc.) as a measuring device according to abubble point method (in conformity with JIS K 3832). Here, the maximumpore diameter is a value of the largest pore diameter in a pore diameterdistribution of a porous film.

The thickness of the porous film 2 is preferably in a range of 1 μm to100 μm.

Moreover, it is preferable that the surface on the side of the porousfilm 2 in contact with at least the facilitated transport film 5 is ahydrophobic surface. When the surface is hydrophilic, the facilitatedtransport film containing moisture easily permeates into a porousportion in a usage environment and thereby a film thickness distributionor aging performance may deteriorate.

Here, hydrophobicity indicates that the contact angle of water at roomtemperature (25° C.) is 80° C. or higher.

In the present invention, the porous film 2 is a porous resin sheetformed of resin materials such as polyester, polyolefin, polyamide,polyimide, polysulfoneamide, polysulfone, polycarbonate, andpolyacrylonitrile.

The acidic gas separation module to which the acidic gas separationlaminate of the present invention is applied is frequently used in ahumidified environment in which vapor is used at a high temperature ofapproximately 130° C. even though the temperature of use variesdepending on the application thereof. For this reason, it is preferablethat the porous film has heat resistance with less change in porestructure even at a temperature of 130° C. and is formed of a materialwith less hydrolyzability. From this viewpoint, it is preferable thatthe porous film is formed by including a resin selected from a groupconsisting of fluorine-containing resins such as polypropylene,polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF). Inaddition, a PTFE porous film is most preferable.

(Auxiliary Support Film)

The auxiliary support film 3 is provided for reinforcing the porous film2 and is not particularly limited as long as the strength, drawingresistance, and gas permeability thereof are excellent. A non-wovenfabric, a woven fabric, a knitted fabric, and a mesh having a maximumpore diameter of 0.001 μm to 500 μm can be appropriately selected to beused.

The thickness of the auxiliary support film 3 is preferably in a rangeof 50 μm to 300 μm.

It is preferable that the auxiliary support film 3 is formed of amaterial which has heat resistance and less hydrolyzability similar tothe porous film 2 described above. As fibers constituting non-wovenfabric, woven fabric, or knitted fabric, fibers formed offluorine-containing resins, for example, modified polyamide such aspolypropylene or aramide; polytetrafluoroethylene; and polyvinylidenefluoride which have excellent durability and heat resistance arepreferable. It is preferable that the same materials are used as resinmaterials constituting the mesh.

Among these materials, it is particularly preferable that a non-wovenfabric formed of polypropylene (PP) which is inexpensive and has highmechanical strength is used.

(Permeating Gas Channel Member)

The permeating gas channel member 6 is a member which reacts with acarrier and in which acidic gas permeated and passed through the gasseparation film 10 flows. It is preferable that the permeating gaschannel member 6 is formed of an uneven member with open gaps such thatthe permeating gas channel member 6 has a function as a spacer, afunction of allowing acidic gas to flow into the permeating gascollecting pipe side, and a function of allowing an adhesive describedbelow to become impregnated. The shape of tricot knitting or plain weaveis exemplified. Further, when a raw material gas containing water vaporat a high temperature is assumed, preferably, the permeating gas channelmember has moist heat resistance similar to the gas separation film.

As specific examples of materials used for the permeating gas channelmember 6, polyester-based materials such as epoxy-impregnated polyester;polyolefin-based materials such as polypropylene; fluorine-basedmaterials such as polytetrafluoroethylene; and metal-based materialssuch as wire netting are preferable.

The thickness of the permeating gas channel member 6, which is notparticularly limited, is preferably in a range of 100 μm to 1000 μm,more preferably in a range of 150 μm to 950 μm, and still morepreferably in a range of 200 μm to 900 μm.

In addition, as the permeating gas channel member, one sheet of one kindof member may be used, but members of the same kind or members of pluralkinds may be laminated on each other for use.

<Adhesive>

In the present invention, adhesives 8 a and 8 b used for the sealingunit 7 and the film protection unit 9 have moist heat resistance.

The material of the adhesive is not particularly limited as long as thematerial has moist heat resistance, and examples thereof include anepoxy resin, a vinyl chloride copolymer, a vinyl chloride-vinyl acetatecopolymer, a vinyl chloride-vinylidene chloride copolymer, a vinylchloride-acrylonitrile copolymer, a butadiene-acrylonitrile copolymer, apolyamide resin, polyvinyl butyral, polyester, a cellulose derivative(nitrocellulose or the like), a styrene-butadiene copolymer, varioussynthetic rubber resins, a phenol resin, a melamine resin, a phenoxyresin, a silicone resin, and a urea formamide resin.

An epoxy resin is particularly preferable.

Further, for the purpose of improving wettability of an adhesive, amaterial containing a solvent or a surfactant may be used.

In addition, since the respective suitable viscosities of an adhesivewhich is initially applied to form a film protection unit and has arelatively low viscosity and an adhesive which is subsequently appliedto form a sealing unit and has a relatively high viscosity varydepending on the materials of the porous film and the porous supportfilm, the thicknesses of respective films, the pore diameter, and thepore density, the viscosity is adjusted using an appropriate solvent orthe like according to the materials of the porous film, the auxiliarysupport film, and the adhesive to be used and then the adhesives areused.

In a particularly preferable form of the laminate 1, the porous film 2is a PTFE porous sheet, the auxiliary support film 3 uses the poroussupport 4 which is PP unwoven fabric, the channel member 6 uses PP wovenfabric, and an epoxy resin is used as the adhesive 8 used for thesealing unit 7.

Further, the gas separation film 10 having the facilitated transportfilm 5 on the support 4 may have another layer other than thefacilitated transport film 5 on the support 4. As another layer, anundercoat layer provided between the porous support 4 and thefacilitated transport film 5, an intermediate layer, or a protectivelayer (for example, a carrier elution preventing layer) provided on thefacilitated transport film 5 is exemplified.

FIG. 1E is a perspective view schematically illustrating a laminationconfiguration of the acidic gas separation laminate 11 according to adesign modification example of the embodiment. In the laminate 11 of theexample, an acidic gas separation film 17 of the above-describedlaminate 1 includes an intermediate layer 15 between the porous support4 and the facilitated transport film 5.

As described above, since the facilitated transport film needs to hold alarge amount of moisture in the film for the purpose of allowingsufficient functioning of a carrier, a hydrophilic compound havingextremely high water absorption properties and water retentionproperties is used. Further, in the facilitated transport film, as thecontent of a carrier such as a metal carbonate becomes larger, theamount of water adsorption increases and separation performance ofacidic gas improves. For this reason, the facilitated transport film isa gel film or a film having low viscosity in many cases. Accordingly,from a viewpoint that the porous film of the acidic gas separation filmsuppresses impregnation of a facilitated transport material at the timeof formation of a facilitated transport film, it is preferable that thesurface on the side in contact with at least the facilitated transportfilm has hydrophobicity. However, even when a hydrophobic porous film isincluded, since a raw material gas in a temperature range of 100° C. to130° C. at a humidity of approximately 90% is supplied at a pressure ofapproximately 1.5 MPa at the time of separating out acidic gas, due tothe use thereof, there is a tendency that the facilitated transport filmgradually enters the porous support and a separation capacity of theacidic gas decreases with time.

Consequently, it is preferable that the acidic gas separation filmincludes the intermediate layer 15, which more effectively suppressesimpregnation of the facilitated transport material (film) into theporous film, between the porous film and the facilitated transport film.

(Intermediate Layer)

The intermediate layer 15 is not particularly limited as long as thelayer has hydrophobicity with gas permeability, but it is preferablethat the intermediate layer 15 has air conductivity and is a layerdenser than the porous film. When the intermediate layer 15 is included,it is possible to prevent the facilitated transport film 5 having highuniformity from entering the porous film 2.

The intermediate layer 15 may be formed on the porous film 2 or may havea impregnation region which becomes impregnated into the porous film 2.It is preferable that the impregnation region is smaller within a rangein which adhesion properties of the porous film 2 to the intermediatelayer 15 are excellent.

As the intermediate layer 15, a polymer layer having a siloxane bond ina repeating unit is preferable. Examples of such a polymer layer includesilicone-containing polyacetylene such as organopolysiloxane (a siliconeresin) or polytrimethyl silyl propyne. As a specific example of theorganopolysiloxane, an organopolysiloxane represented by the followingformula is exemplified.

In the formula above, n represents an integer of 1 or greater. Here,from viewpoints of availability, volatility, and viscosity, the averagevalue of n is preferably in a range of 10 to 1,000,000 and morepreferably in a range of 100 to 100,000.

In addition, R_(1n), R_(2n), R₃, and R₄ each independently represent anyone selected from a group consisting of a hydrogen atom, an alkyl group,a vinyl group, an aralkyl group, an aryl group, a hydroxyl group, anamino group, a carboxyl group, and an epoxy group. Further, n number ofR_(1n)'s and R_(2n)'s may be the same as or different from each other.In addition, an alkyl group, an aralkyl group, and an aryl group mayhave a ring structure. Further, the alkyl group, the vinyl group, thearalkyl group, and the aryl group may include a sub stituent and thesubstituent is selected from an alkyl group, a vinyl group, an arylgroup, a hydroxyl group, an amino group, a carboxyl group, an epoxygroup, and a fluorine atom. These substituents can further include asubstituent if possible.

As an alkyl group, a vinyl group, an aralkyl group, and an aryl groupselected for R_(1n), R_(2n), R₃, and R₄, from a viewpoint ofavailability, an alkyl group having 1 to 20 carbon atoms, a vinyl group,an aralkyl group having 7 to 20 carbon atoms, and an aryl group having 6to 20 carbon atoms are more preferable.

Particularly, it is preferable that R_(1n), R_(2n), R₃, and R₄ representa methyl group or an epoxy-substituted alkyl group, and epoxy-modifiedpolydimethyl siloxane (PDMS) or the like can be suitably used.

It is preferable that a silicone resin layer is formed by forming acoating film. A coating solution (silicone coating solution) used forfilm formation may include a monomer, a dimer, a trimer, an oligomer, ora prepolymer of a compound which becomes a silicone resin layer, or amixture of these. The silicone resin layer may further include a curingagent, a curing accelerator, a crosslinking agent, a thickener, or areinforcing agent.

The intermediate layer 15 is a film having gas permeability, but the gaspermeability can be significantly degraded when the thickness thereof islarge. The intermediate layer 15 may be thin if the intermediate layerentirely covers the surface of the porous film 2 without any space left.From this viewpoint, the film thickness of the intermediate layer 15 ispreferably in a range of 0.01 μm to 30 μm and more preferably in a rangeof 0.1 μm to 15 μm.

[Method of Producing Acidic Gas Separation Laminate]

Next, a method of producing the laminate 1 of the embodiment will besimply described with reference to FIGS. 2A to 2D. FIGS. 2A to 2D arepartially enlarged sectional views respectively illustrating aproduction process.

First, the porous support 4 formed by laminating the porous film 2 andthe auxiliary support film 3 on each other is prepared.

Further, a coating composition used to form an acidic gas separationfacilitated transport film is adjusted. The coating composition isprepared by adding appropriate amounts of the hydrophilic polymer, anacidic gas carrier (for example, a carbon dioxide carrier), and water,and other additives such as a gelling agent and a crosslinking agent ifnecessary to water (room temperature water or pressurized hot water),sufficiently stirring the mixture, and heating the mixture while themixture is stirred if necessary to promote dissolution. Further, ahydrophilic polymer, an acidic gas carrier, and other components may beindividually added to water or may be mixed with each other in advancewith the resulting mixture being added to water.

As illustrated in FIG. 2A, the porous film 2 of the porous support 4 iscoated with the coating composition and dried, thereby forming thefacilitated transport film 5 on the porous support 4. A gas separationcomposite film of the porous support 4 and the facilitated transportfilm 5 is the gas separation film 10.

Subsequently, as illustrated in FIG. 2B, the auxiliary support film 3 isset to be the upper surface and three sides from the peripheral edge ofthe auxiliary support film are coated with the adhesive 8 a using abrush 11 from the auxiliary support film 3 side. At this time, theadhesive 8 a passes through the mesh of the auxiliary support film 3without remaining in the mesh at the time of application and becomesimpregnated into the pores of the porous film 2 by adjusting theviscosity of the adhesive 8 a to be relatively low. The adhesive 8 aremains in the pores of the porous film 2 without being impregnated intothe separation film.

Next, as illustrated in FIG. 2C, the adhesive 8 b is applied to threesides, in which the front of the peripheral edge of the auxiliarysupport film 3 is coated with the adhesive 8 a, over a width narrowerthan the width of the adhesive 8 a (see FIG. 4A). Further, the viscosityof the adhesive 8 b is adjusted to be higher than that of the adhesive 8a used for application of the adhesive previously.

Next, as illustrated in FIG. 2D, the adhesive 8 b becomes impregnatedinto the eyes (pores) of the auxiliary support film 3 and the channelmember 6 due to placing the gas separation film 10 on the channel member6 such that the gas separation film 10 is brought into contact with thecoating surface of the adhesive 8 b (alternatively, placing the channelmember 6 on the coating surface of the adhesive 8 b of the gasseparation film 10) and applying tension thereto in the film surfacedirection.

As a result, the sealing unit 7 formed by the adhesive 8 continuouslypermeating into the porous film 2, the auxiliary support film 3, and thegas channel member 6 in the lamination direction is formed asillustrated in FIG. 2D. At this time, since the adhesive spreadscentering on the coating unit, the spreading region of the adhesivebecomes non-uniform in the lamination direction in many cases.

Further, the coating amount of the adhesive 8 b having a high viscosityin the permeation region is adjusted such that the width thereof isnarrower than that of the permeation region of the adhesive 8 a in theporous film. In this manner, the film protection unit 9 is formed in astate of being adjacent to the sealing unit 7 as illustrated in FIG. 1B.

Finally, the end portion illustrated in FIG. 2D is cut at the positionof the C-C line, so-called trimming (end surface modifying process) isperformed, and the laminate 1 is obtained.

In an initial adhesive application process of applying the adhesive 8 ahaving a relatively low viscosity, a method of using the brush 11 issuitably used.

In a second adhesive application process of applying the adhesive 8 bhaving a relatively high viscosity, as illustrated in FIGS. 3A and 3B, aslot die 60 can be used. The separation film 10 is conveyed in an Adirection using a conveying roller 65 as illustrated in FIG. 3A and thenthe adhesive 8 b may be applied using the slot die 60, or the adhesive 8b may be applied while the separation film 10 is conveyed in a directionB perpendicular to the slot die 60 as illustrated in FIG. 3B.

Alternatively, as illustrated in the plan view of FIG. 4A and a sideview of FIG. 4B, a method of applying the adhesive 8 b by pressing asponge 72 into which the adhesive 8 b becomes impregnated into thesurface of the separation film 10 (surface of the auxiliary supportfilm) using a stamp 70 including the sponge 72 in the form correspondingto a coating area may be used.

When these adhesive application methods are used, automation of theproduction process becomes easy and uniform application can be performedby controlling the application amount and the application width.

The acidic gas separation laminate of the present invention is used bybeing incorporated in the acidic gas separation module. The acidic gasseparation module of the present invention includes a permeating gascollecting pipe and the laminated film of the present invention which isconnected to the collecting pipe. As the form of the acidic gasseparation module, various kinds of module form such as a spiral typemodule and a flat film type module can be employed.

The laminate illustrated in FIG. 1A described above has a configurationof a minimum unit of the present invention, but the laminate of thepresent invention can be used by appropriately changing theconfiguration according to the module configuration to be applied.

Further, as illustrated in FIG. 8I, a laminate which includes the supplygas channel member 30 that is disposed between the acidic gas separationfacilitated transport films 5 of the acidic gas separation film 10 thatis obtained by inwardly folding the acidic gas separation facilitatedtransport film 5 into two on the channel member 6 in the lengthdirection and in which the film protection unit 19 is formed on aportion overlapping the portion of the acidic gas separation facilitatedtransport film 5 with which an end portion of the supply gas channelmember 30 is brought into contact is one form of the acidic gasseparation laminate of the present invention. At this time, the filmprotection unit 19 is not formed adjacent to the sealing unit and may beindividually formed. In this case, in the film protection unit 19, theimpregnation rate of the adhesive in the porous film 2 may be 10% orgreater, more preferably 40% or greater, and still more preferably 60%or greater. The impregnation rate of the adhesive in the auxiliarysupport film 3 is smaller than the impregnation rate in the porous film2.

Such a film protection unit 19 is formed by coating the auxiliarysupport film 3 side with the adhesive. As the adhesive, the adhesive 8 awhich passes through the pores of the auxiliary support film 3, does notalmost remain in the auxiliary support film 3, and has such a viscositythat the adhesive permeats into the pores of the porous film 2 may beused.

[Acidic Gas Separation Module]

Hereinafter, the acidic gas separation module to which the acidic gasseparation laminate of the present invention is applied will bedescribed in detail.

<Spiral Type Acidic Gas Separation Module>

FIG. 5 is a configuration view schematically illustrating a spiral typeacidic gas separation module 100 (hereinafter, referred to as a spiraltype module 100) which is the first embodiment of the acidic gasseparation module of the present invention by cutting out a partthereof.

As illustrated in FIG. 5, as a basic structure, the spiral type module100 is configured such that the outermost periphery thereof is coveredby a coating layer 16 in a state in which one or a plurality oflaminates 14 described below is wound around the permeating gascollecting pipe 12 and telescoping prevention plates 18 are respectivelyattached to both ends of these units. When raw material gas 20containing acidic gas is supplied to the laminate 14 from one endportion 100A side, the module 100 having such a configuration separatesthe raw material gas 20 into acidic gas 22 and residual gas 24 andseparately discharges the acidic gas 22 and the residual gas 24 toanother end portion 100B side by using the configuration of the laminate14 described below.

FIG. 6 is a perspective view illustrating a state before the laminate 14is wound around the permeating gas collecting pipe 12 and FIG. 7 is asectional view illustrating a part of a cylindrical wound body obtainedby winding the laminate around the permeating gas collecting pipe.

The permeating gas collecting pipe 12 is a cylindrical pipe in whosewall a plurality of through-holes 12A is formed. One end portion side(one end portion 100A side) of the permeating gas collecting pipe 12 isclosed and another end portion side of the pipe (another end portion100B side) is open and becomes a discharge port 26 from which there ispermeation from the laminate and from which the acidic gas 22 such ascarbon dioxide is collected from the through-holes 12A is discharged.

The shape of the through-hole 12A is not particularly limited, but it ispreferable that a circular hole having a diameter of 0.5 mmφ to 20 mmφis open. Further, it is preferable that the through-holes 12A areuniformly arranged with respect to the surface of the permeating gascollecting pipe 12.

The coating layer 16 is formed of a blocking material which can blockthe raw material gas 20 from passing through the acidic gas separationmodule 100. It is preferable that the blocking material further hasmoist heat resistance. Here, “heat resistance” in moist heat resistanceindicates resistance to heat at a temperature of 80° C. or higher.Specifically, heat resistance at 80° C. or higher means that the shapebefore storage is maintained after storage for 2 hours under atemperature condition of 80° C. or higher and curls which are generateddue to thermal contraction or thermofusion and can be visually confirmedare not generated. Further, “moist resistance” in moist heat resistancemeans that the shape before storage is maintained after storage for 2hours under the conditions of a temperature of 40° C. and a relativehumidity of 80% and curls which are generated due to thermal contractionor thermofusion and can be visually confirmed are not generated.

The telescope prevention plate 18 includes an outer peripheral circularportion 18A, an inner peripheral circular portion 18B, and a radialspoke portion 18C and it is preferable that the respective portions areformed of materials having moist heat resistance.

The laminate 14 is configured by laminating the permeating gas channelmember 6 to a leaf 50 which is formed by a supply gas channel member 30being interposed between the acidic gas separation film 10 obtained byinwardly folding the facilitated transport film 5 into two. The acidicgas separation film 10 includes the porous support 4 formed bylaminating the porous film 2 and the auxiliary support film 3 and theacidic gas separation facilitated transport film 5 including an acidicgas carrier that is disposed on the porous film 2 side of the poroussupport 4 and reacts with at least a hydrophilic compound and acidic gasin raw material gas. In addition, the acidic gas separation film 10 andthe permeating gas channel member 6 include the sealing unit 7 and thefilm protection unit 9 on the three sides from the peripheral edge ofthe laminate 14. Further, the folded portion of the acidic gasseparation film 10 which is folded into two includes the film protectionunit 9. Moreover, the acidic gas separation film 17 including theintermediate layer 15 between the porous support 4 and the facilitatedtransport film 5 may be used in place of the acidic gas separation film10.

The laminate 14 is a form of the acidic gas separation laminate of thepresent invention. That is, the sealing unit 7 has a impregnation rateof the adhesive in the porous film 2 of 60% or greater and aimpregnation rate of the adhesive in the auxiliary support film 3 andthe permeating gas channel member 6 of greater than or equal to theimpregnation rate of the adhesive in the porous film 2. The sealing unit7 is formed to have a width of 5 mm or greater from the end portion ofthe laminate and the film protection unit 9 is formed in a state ofbeing adjacent to the sealing unit 7. The details of the sealing unit 7and the film protection unit 9 are the same as the case of the laminate1 described above.

The number of sheets of the laminates 14 to be wound around thepermeating gas collecting pipe 12 is not particularly limited. One sheetor plural sheets of laminates may be used, but the film area of thefacilitated transport film 5 can be improved by increasing the number ofsheets (number of laminations). In this manner, the amount of the acidicgas 22 which can be separated out by one module can be increased.Further, the length of the laminate 14 may be further increased in orderto improve the film area.

In addition, in a case where the number of sheets of the laminates 14 isplural, the number thereof is preferably 50 sheets or less, morepreferably 45 sheets or less, and still more preferably 40 sheets orless. When the number of sheets is less than or equal to theabove-described range, the winding of the laminate 14 becomes easy andthe processing suitability is improved.

The width of the laminate 14, which is not particularly limited, ispreferably in a range of 50 mm to 10000 mm, more preferably in a rangeof 60 mm to 9000, and still more preferably in a range of 70 mm to 8000mm. In addition, from a practical viewpoint, it is preferable that thewidth of the laminate 14 is in a range of 200 mm to 2000 mm. When thewidth thereof is adjusted to be greater than or equal to each of thelower limits, an effective film area of the acidic gas separation film10 can be secured even when a resin is applied (sealed). Further, whenthe width thereof is adjusted to be less than or equal to each of theupper limits, horizontality of a winding core is maintained andgeneration of winding deviation can be suppressed.

In the spiral type module, the laminate 14 is wound around thepermeating gas collecting pipe 12 in an arrow C direction as illustratedin FIG. 6 and a configuration in which the laminate 14 is laminated onthe permeating gas channel member 6 wound around the permeating gascollecting pipe 12 in the section is included as illustrated in FIG. 7.The laminates 14 are bonded to each other through the sealing unit 7 atboth ends thereof. In this configuration, the raw material gas 20containing the acidic gas 22 is supplied from the end portion of thesupply gas channel member 30, the acidic gas 22 separated by permeatinginto the acidic gas separation film 10 is collected in the permeatinggas collecting pipe 12 via the permeating gas channel member 6 and thethrough-holes 12A, and the gas is recovered through the discharge port26 connected to the permeating gas collecting pipe 12. Further, theresidual gas 24, which is separated from the acidic gas 22, passingthrough spaces and the like of the supply gas channel member 30 isdischarged from the end portion of the supply gas channel member 30 onthe side of the discharge port 26 provided in the acidic gas separationmodule 100.

As illustrated in FIG. 6, the through-holes 12A are covered by thepermeating gas channel member 6 by allowing the permeating gascollecting pipe 12 to rotate in an arrow C direction in the figure, andthe acidic gas separation film 10 and the permeating gas channel member6 are bonded to each other to form a sealing unit 7 using the adhesive 8applied to the front and rear surfaces of the gas separation film 10folded into two in a state of the supply gas channel member 30 beinginterposed therebetween when the laminate 14 is wound around thepermeating gas collecting pipe multiple times.

The sealing unit 7 is not provided in the end portion on the collectingpipe 12 side arranged along the permeating gas collecting pipe 12between the winding start acidic gas separation film 10 and thepermeating gas channel member 6 and channels P1 and P2 in which theacidic gas 22 having permeated and passed through the acidic gasseparation film 10 flows into the through-holes 12A are formed in theregion surrounded by the sealing unit 7.

Respective elements of the laminate 14 applied to the acidic gasseparation module are the same as the constituent elements denoted bythe same reference numerals in the acidic gas separation laminate 1described above. The laminate 14 of the acidic gas separation modulefurther includes the supply gas channel member 30.

(Supply Gas Channel Member)

The supply gas channel member 30 is a member to which raw material gascontaining acidic gas is supplied from one end portion of the acidic gasseparation module, has a function as a spacer, and allows turbulence tobe generated in the raw material gas, which is preferable, and thus anet-like member is preferably used as the supply gas channel member 30.Since a channel of gas is changed due to the shape of a net, the shapeof a net unit lattice is selected from the shapes of a diamond, aparallelogram, and the like for use. In addition, when it is assumedthat raw material gas containing water vapor at a high temperature issupplied, it is preferable that the supply gas channel member 30 hasmoist heat resistance similar to the gas separation film 10.

The material of the supply gas channel member 30 is not particularlylimited and examples thereof include resin materials such as paper,high-quality paper, coated paper, cast-coated paper, synthetic paper,cellulose, polyester, polyolefin, polyamide, polyimide, polysulfone,aramide, and polycarbonate; and inorganic materials such as metals,glasses, and ceramics. Preferred examples of the resin materials includepolyethylene, polystyrene, polyethylene terephthalate,polytetrafluoroethylene (PTFE), polyethersulfone (PES), polyphenylenesulfide (PPS), polysulfone (PSF), polypropylene (PP), polyimide,polyetherimide, polyether ether ketone, and polyvinylidene fluoride.

From a viewpoint of moist heat resistance, preferred examples of thematerials include inorganic materials such as ceramics, glasses, andmetals; and organic resin materials having heat resistance at atemperature of 100° C. or higher, and high-molecular-weight polyester,polyolefin, heat-resistant polyamide, polyimide, polysulfone, aramide,polycarbonate, metals, glasses, and ceramics can be suitably used. Morespecifically, it is preferable that the supply gas channel member 30 isconfigured by including at least one material selected from a groupconsisting of ceramics, polytetrafluoroethylene, polyvinylidenefluoride, polyethersulfone, polyphenylene sulfide, polysulfone,polyimide, polypropylene, polyetherimide, and polyether ether ketone.

The thickness of the supply gas channel member 30, which is notparticularly limited, is preferably in a range of 100 μM to 1000 μM,more preferably in a range of 150 μm to 950 μm, and still morepreferably in a range of 200 μm to 900 μm.

<Method of Producing Spiral Type Module>

Next, a method of producing the acidic gas separation module having theabove-described configuration will be described. FIGS. 8A to 8H areviews for describing a process of producing the acidic gas separationmodule.

First, as illustrated in FIG. 8A, the tip portion of the long permeatinggas channel member 6 is put inside a slit (not illustrated) provided inthe axial direction of the pipe wall of the permeating gas collectingpipe 12. According to this configuration, even when the laminate 14including the permeating gas channel member 6 is wound around thepermeating gas collecting pipe 12 while tension is applied thereto, thepermeating gas channel member 6 does not come out of the slit due tofriction between the inner peripheral surface of the permeating gascollecting pipe 12 and the permeating gas channel member 6, that is, thefixation of the permeating gas channel member 6 is maintained. Further,in a case where the permeating gas collecting pipe 12 does not include aslit, the tip portion of the permeating gas channel member may be fixedto the pipe wall (outer peripheral surface) of the permeating gascollecting pipe 12 using a fixing member such as a Kapton tape or anadhesive.

Next, the gas separation film 10 formed by coating the porous support 4obtained by laminating the porous film 2 and the auxiliary support film3 on the facilitated transport film 5 is prepared, a supply gas channelmember 30 is placed in a region which is half of the surface of thefacilitated transport film 5 of the gas separation film 10 asillustrated in FIG. 8B, and the gas separation film 10 is folded intotwo in a direction of an arrow D as illustrated in FIG. 8C such that thesupply gas channel member 30 is interposed between the facilitatedtransport films 5. Further, when the acidic gas separation film 10 isfolded into two, the acidic gas separation film 10 may be divided intotwo as illustrated in FIG. 8C, but the film may be shifted and thenfolded.

As illustrated in FIG. 8C, after a leaf 50 in which the long supply gaschannel member 30 is interposed between the long acid gas separationfilm 10 obtained by inwardly folding the facilitated transport film 5 isformed, four sides shown by the hatching of one surface 50 a of the leafin the figure are coated with the adhesive 8 a using the brush 11 or thelike. At this time, the adhesive 8 a passes through the mesh of theauxiliary support film 3 without remaining in the mesh at the time ofapplication and has become impregnated into the pores of the porous film2 by adjusting the viscosity of the adhesive 8 a to be relatively low.The adhesive 8 a remains in the pores of the porous film 2 without beingimpregnated into the facilitated transport film 5 (see FIG. 8D).

As illustrated in FIG. 8D, after the adhesive 8 a becomes impregnatedinto the porous film 2 of the one surface 50 b side of the leaf 50,three sides from which a folded portion 51 of the one surface 50 a(surface of the auxiliary support film 3 of the porous support 4) of theleaf 50 is removed is coated with the adhesive 8 b as illustrated inFIG. 8E. The viscosity of the adhesive 8 b is adjusted to be higher thanthat of the adhesive 8 a used for application of the adhesivepreviously. The adhesive 8 b may be applied appropriately using themethod described in the first embodiment. Further, the application widthof the adhesive 8 b is set to be smaller than that of the adhesive 8 a.

Next, as illustrated in FIG. 8F, the leaf 50 is placed on the surface ofthe permeating gas channel member 6 fixed to the permeating gascollecting pipe 12 such that the leaf 50 is brought into contact withthe surface 50 a coated with the adhesive 8 b. At this time, the foldedportion 51 of the leaf 50 which is not coated with the adhesive 8 b isset to be the gas collecting pipe 12 side.

Next, as illustrated in FIG. 8G, in the same manner as described above,four sides shown by the hatching of another surface 50 b of the leaf 50adhered to the permeating gas channel member 6 in the figure are coatedwith the adhesive 8 a using the brush 11 or the like. At this time, theadhesive 8 a passes through the mesh of the auxiliary support film 3without remaining in the mesh at the time of application and becomesimpregnated into the pores of the porous film 2 as illustrated in FIG.8H. The adhesive 8 a remains in the pores of the porous film 2 withoutbeing impregnated into the facilitated transport film 5.

FIG. 8I is an enlarged view of the section taken along the line 8I-8I inFIG. 8H. When an area from the one surface 50 a and another surface 50 bof the leaf 50 to the folded portion 51 is coated with the adhesive 8 a,the adhesive 8 a becomes impregnated into the porous film 2 of thefolded portion 51 of the gas separation film 10 at an impregnation rateof 10% or greater, and the film protection unit 19 in which theimpregnation rate of the adhesive in the auxiliary support film 3 issmaller than the impregnation rate of the adhesive in the porous film 2is formed. As described above, the film protection unit 19 is notprovided adjacent to the sealing unit. The film protection unit 19prevents the facilitated transport film 5 in the folded portion frombeing damaged and prevents leakage of gas in a case where damage occurs.

As illustrated in FIG. 8I, damage or a defect 5 a tends to occur in thefacilitated transport film 5 at a portion in which the center of thefolded portion of the gas separation film 10 is brought into contactwith the corners of the supply gas channel member 30. When damage or adefect occurs in the facilitated transport film 5, there is a concernthat supply gas may be mixed into the permeating gas channel member sidedue to the damage or the defect. However, as described in theembodiment, since the porous film 2 of the folded portion includes thefilm protection unit 19 into which the adhesive 8 a becomes impregnated,it is possible to prevent the supply gas from leaking to the permeatinggas channel member side after permeating into the separation film 10.

Next, three sides of the peripheral edge of another surface 50 b of theleaf 50 attached to the permeating gas channel member 6 are coated withthe adhesive 8 b in the same manner as described above.

Subsequently, as schematically illustrated in FIG. 9, the permeating gaschannel member 6 is wound around the permeating gas collecting pipe 12so as to cover the through-holes 12A by allowing the permeating gascollecting pipe 12 to rotate in an arrow C direction, and the leaf 50 isfurther wound around the permeating gas channel member 6. At this time,when tension is applied to the film direction, the sealing unit 7 isformed by the adhesive 8 b, which is applied to one surface 50 a of theleaf 50, permeating into the channel member 6 and the porous support 4and the sealing unit 7 is formed by the adhesive 8 b, which is appliedto another surface 50 b of the leaf 50, permeating into the permeatinggas channel member 6 and the porous support 4. In this manner, asillustrated in FIG. 7, a spiral module including the sealing unit 7formed by the adhesive 8 b permeating into the both end portions of thecollecting pipe 12 in the length direction and the film protection unit9 adjacent to the sealing unit 7 which is formed by the permeation ofthe adhesive 8 a can be obtained.

Plural sheets of leaves 50 in which the acidic gas separation film 10 isfolded into two and the supply gas channel member 30 is interposedtherebetween and plural sheets of permeating gas channel members 6 arealternately laminated on each other. As a result, the plural laminates14 overlap each other as illustrated in FIG. 10 and then may be woundaround the permeating gas collecting pipe multiple times. In addition,in the case where the plural laminates overlap each other, it ispreferable that the laminates overlap so as to be slightly shifted fromeach other as illustrated in FIG. 10 such that differences betweenlevels after the laminate is wound around the collecting pipe do notbecome large.

A cylindrical wound body is obtained by performing the above-describedprocess, trimming (end surface modifying process) is performed on bothend portions of the obtained cylindrical wound body, the outermostperiphery of the cylindrical wound body is covered by the coating layer16, and the telescope prevention plate 18 is attached to both endsthereof, thereby obtaining the acidic gas separation module 100illustrated in FIG. 5.

In the embodiment of the spiral module, the film protection unit 19 isformed in the folded portion 51 of the leaf 50, but the film protectionunit 19 is not necessarily included when the folded portion 51 isprotected by adhering a Kapton tape thereto. In a case where the filmprotection unit 19 is not included in the folded portion 51, in theproduction method described above, three sides from which the foldedportion 51 is removed may be coated with the adhesive 8 a applied tofour sides of the leaf 50. However, when the film protection unit 19 isincluded, the separation precision can be further increased, which ispreferable (see Examples described below).

<Flat Film Type Acidic Gas Separation Module>

FIG. 11 is a perspective view schematically illustrating a flat filmtype acidic gas separation module 110 (hereinafter, referred to as aflat film type module 110) which is a second embodiment of the acidicgas separation module of the present invention and FIG. 12 is asectional view taken along the line XII-XII of FIG. 11.

As illustrated in FIGS. 11 and 12, the flat film type module 110includes a permeating gas collecting pipe 112 and a laminate 114including separation films 10 and 10A on both surfaces of the permeatinggas channel member 6.

The laminate 114 is an embodiment of the acidic gas separation laminateof the present invention and includes the porous support 4 formed bylaminating the porous film 2 and the auxiliary support film 3, theacidic gas separation film 10 formed of the acidic gas separationfacilitated transport film 5 including an acidic gas carrier that isdisposed on the porous film 2 side of the porous support 4 and reactswith at least a hydrophilic compound and acidic gas in raw material gas,and a permeating gas channel member 6 which is disposed on the auxiliarysupport film 3 side of the porous support 4 and in which the acidic gashaving permeated and passed through the acidic gas separationfacilitated transport film 5 flows by reacting with the acidic gascarrier. In addition, in the embodiment, one more acidic gas separationfilm 10A interposing the permeating gas channel member 6 and facing theacidic gas separation film 10 may be included. Here, the acidic gasseparation film 17 including the intermediate layer 15 between theporous support 4 and the facilitated transport film 5 may be used inplace of the acidic gas separation films 10 and 10A.

Further, the laminate includes the sealing unit 7 formed by the adhesive8 permeating into the porous film 2, the auxiliary support film 3, andthe permeating gas channel member 6 in the lamination direction at awidth of 5 mm or greater in the peripheral edge of the laminate 114 andthe film protection unit 9 formed in a state of being adjacent to thesealing unit 7. The sealing unit 7 and the film protection unit 9 areprovided on three sides from the peripheral edge of the laminate 114 andone side which is not provided with the sealing unit 7 and the filmprotection unit 9 is connected to the permeating gas collecting pipe112. The permeating gas permeating into the acidic gas separation films10 and 10A passes through the inside region surrounded by the sealingunit 7 of the permeating gas channel member 6 and flows into thepermeating gas collecting pipe 112.

The flat film type module 110 is arranged in a container to which rawmaterial gas is supplied. Further, the acidic gas 22 in the raw materialgas 20 reacts with a carrier of the facilitated transport film 5, istaken into the laminate 114, permeates and passes through thefacilitated transport film 5 and the porous support 4, passes throughthe permeating gas channel member 6, is accumulated in the permeatinggas collecting pipe 112, and recovered by a gas exhaust port (notillustrated) connected to the permeating gas collecting pipe 112.

Since the flat film type module of the embodiment includes the laminate114 and the film protection unit 9 in a state of being adjacent to thesealing unit 7, it is possible to prevent the facilitated transport film5 from being damaged due to stress concentration occurring in theinterface between the sealing unit 7 and a portion other than thesealing unit. Further, even when damage is generated, it is possible toprevent raw material gas from permeating into the permeating gas channelmember 6 side from the damaged region of the facilitated transport film5.

EXAMPLES

Hereinafter, the present invention will be described in detail withreference to Examples. Further, the materials, the amounts used, theproportions, the treatment details, and the treatment procedures shownin Examples below can be appropriately changed within a range notdeparting from the scope of the present invention. Accordingly, therange of the present invention should not be limitatively interpreted bythe specific examples described below.

Example 1

As a porous support formed of a laminated film of a porous film and anauxiliary support film, PTFE/PP unwoven fabric (manufactured by GeneralElectric Company) was used. The thickness of the PTFE was approximately30 μm and the thickness of the PP unwoven fabric was approximately 200μm.

(Preparation of Coating Solution Composition of Carbon DioxideSeparation Facilitated Transport Film)

1 M hydrochloric acid was added to an aqueous solution containing 3.3%by mass of a polyvinyl alcohol polyacrylic acid copolymer KURASTOMERAP20 (manufactured by KURARAY CO., LTD.) and 0.016% by mass of a 25%glutaraldehyde aqueous solution (manufactured by Wako Pure ChemicalIndustries, Ltd.) such that cross-linking occurred, and a 40% cesiumcarbonate (manufactured by Kisan Kinzoku Chemicals Co., Ltd.) aqueoussolution serving as a carrier was added thereto such that theconcentration of the cesium carbonate became 6.0% by mass. Further, 1%RAPISOL A-90 (manufactured by NOF CORPORATION) was added thereto suchthat the concentration thereof became 0.004% by mass, the temperaturewas increased, and the mixture was stirred in order to allow degassing,thereby obtaining a coating composition.

The PTFE film of the PTFE/PP unwoven fabric was coated with the coatingcomposition and dried, and then a separation film was formed.

As a supply gas channel member, a polypropylene net having a thicknessof 0.44 mm was interposed between separation film obtained by inwardlyfolding the carbon dioxide separation film surface into two. The portionfolded into two was reinforced by a Kapton tape. A fold was firmlyfolded such that the film surface was not damaged and a leaf was formedin a manner in which curls were not generated.

A process of placing a leaf whose three sides of the peripheral edge ofone surface were coated with an adhesive having a relatively lowviscosity, using a brush, at a predetermined position on a permeatinggas channel member formed of polypropylene fabric which was fixed to acollecting pipe via a partition and had a width of 0.5 mm such that theone surface was brought into contact with the permeating gas channelmember and which was coated with an adhesive having relatively highviscosity, similarly coating another surface of the leaf placed on thechannel member with the adhesive to have a U shape in the same manner asdescribed above, placing a new permeating gas channel member thereon,and placing a new leaf coated with the adhesive was repeatedlyperformed, the number of laminated units, each of which is formed of acombination of one leaf and one sheet of permeating gas channel member,was set as 3, and the laminate was wound around the collecting pipe.Here, an epoxy resin whose viscosity was adjusted was used as anadhesive. The viscosity of the adhesive which was initially applied andhad a relatively low viscosity was set as 10 mPa·s and the viscosity ofthe adhesive which was applied later and had a relatively high viscositywas set as 940 Pa·s. An adhesive (E120HP, manufactured by Henkel JapanLtd., Tokyo) formed of an epoxy resin was used as the adhesive having arelatively high viscosity and a mixture of 50 parts by mass of theadhesive (E120HP, manufactured by Henkel Japan Ltd., Tokyo) formed of anepoxy resin and 50 parts by mass of acetone was used as the adhesivehaving a relatively low viscosity.

Both ends were aligned by a side cut, a PPS (including 40% glass)telescoping prevention plate was attached thereto, and the peripherythereof was reinforced by fiber reinforced plastic (FRP), therebyobtaining a spiral type separation film module. The design film area ofthe spiral type separation film module of Example 1 was set to 1.2 m².Further, according to a measurement method described below, the sealingwidth of the sealing unit was 10 mm and the width of the film protectionunit from the end portion was 50 mm. For the impregnation rate of theadhesive in the film protection unit, this was 28% for the porous film,10% for the auxiliary support film, and 10% for the permeating gaschannel member.

Modules of Examples 2 to 6 and Comparative Examples 1 and 2 wererespectively prepared in the same manner as in Example 1 except that thenumbers of laminated units, the film areas (design), the sealing widths,the widths of the film protection unit, the formation positions of thefilm protection unit, and the impregnation rates of the adhesive in thefilm protection unit were set as in Table 2 below. Further, theexpression “the formation position of the film protection unit is threesides” in Table 2 means that the film protection unit is not present inthe folded unit of the leaf and “the formation position of the filmprotection unit is four sides” means that the film protection unit ispresent in the folded unit of the leaf. In Comparative Example 1, thefilm protection unit was not provided.

Example 7

In Example 1, a laminate including an intermediate layer between theporous film and the facilitated transport film was prepared as a sampleof Example 7.

An intermediate layer coating solution used for forming an intermediatelayer was prepared by adding 4-isopropyl-4′-methyldiphenyliodoniumtetrakis(pentafluorophenyl)borate (manufactured by TOKYO CHEMICALINDUSTRY CO., LTD.) as a curing agent to epoxy-modifiedpolydimethylsiloxane (KF-102, manufactured by Shin-Etsu Chemical Co.,Ltd.) which is a silicone resin. At this time, 0.5% by weight of acuring agent was added to 100 of a silicone resin. The surface of theporous support was coated with this intermediate layer coating solutionusing a roll-to-roll system, ultraviolet rays were applied by a curingdevice to cure the intermediate layer coating solution, and anintermediate layer formed of a silicone resin was formed in the support.The coating solution composition of the carbon dioxide separationfacilitated transport film was applied to the support including theintermediate layer and then an acidic gas separation laminate of Example7 was obtained.

TABLE 2 Formation Impregnation Number of position of rate of adhesivelaminated Film area Sealing Width of film film protec- Intermediate infilm protec- units (design) width protection unit tion unit layer tionunit Example 1 3 1.2 10 50 Three sides — 28 Example 2 3 1.2 10 50 Threesides — 13 Example 3 3 1.2 10 50 Three sides — 61 Example 4 3 1.2 10 50Four sides — 26 Example 5 3 1.2 10 50 Four sides — 88 Example 6 20 30 1050 Four sides — 86 Example 7 3 1.2 10 50 Three sides Present 53Comparative 3 1.2 10 — — — 0 Example 1 Comparative 3 1.2 10 50 Threesides — 6 Example 2

Comparative Example 2 is an example in which a region which is adjacentto the sealing unit and in which the impregnation rate of the adhesivein the porous film is less than 10% is included, the region does notcorrespond to the film protection unit, and the film protection unit isnot included in the same manner as in Comparative Example 2. In thiscase, in Comparative Example 2, the width of a region in which theimpregnation rate of the adhesive in the porous film was less than 10%and the impregnation rate of the adhesive are listed in columns of thewidth of the film protection unit and the impregnation rate of theadhesive in Table 2 for the sake of convenience.

[Evaluation of Carbon Dioxide Separation Spiral Module]

The following evaluation was performed on obtained carbon dioxideseparation spiral modules of Examples and Comparative Examples and theresults thereof were listed in Tables 2 and 3.

<Sealing Width, Width of Film Protection Unit, and Impregnation Rate ofAdhesive>

After module factor evaluation was performed, a module was disassembled,a sealed portion was subjected to freeze-fracture to take a section out,the section was observed using a scanning electron microscope (SEM), andthe width of the sealing unit and the width of the film protection unitwere measured. Specifically, sections were taken out in three differentplaces in a specific side other than the folded unit of the leaf fromthe three sides or the four sides in each laminate, the impregnationrate of the adhesive from the filling area of the adhesive to the areaof pores in respective units of the porous film, the auxiliary supportfilm, and the permeating gas channel member was acquired by performingimage processing on respective sections for each area having a width of0.01 mm from the end portion of the laminate, a portion in which theimpregnation rate of the adhesive in the porous film was 60% or greaterand the respective impregnation rates of the adhesive in the auxiliarysupport film and the permeating gas channel member were greater than orequal to the impregnation rate of the adhesive in the porous film wasset as a sealing unit, and a portion in which the impregnation rate ofthe adhesive in the porous film 2 was 10% or greater and in which theimpregnation rates of the adhesive in the auxiliary support film and thepermeating gas channel member were smaller than the impregnation rate ofthe adhesive in the porous film 2 was set as a film protection unit, andthen the width of the sealing unit and the width of the film protectionunit were acquired. The average value of the widths of the sealing unitin three sections, the widths of the film protection unit, and theimpregnation rates of the adhesive in the film protection unit wererespectively set as the width of the sealing unit of the module, thewidth of the film protection unit, and the impregnation rate of theadhesive in the film protection unit. The results thereof are listed inTable 2.

In Table 2, the impregnation rate of the adhesive in the film protectionunit is the impregnation rate of the adhesive in the porous film of thefilm protection unit.

<Module Factor>

The module factors of the prepared carbon dioxide separation modulesaccording to Examples and Comparative Examples, an acidic gas separationmodule, and an acidic gas separation facilitated transport film on aporous support used in a module were evaluated and calculated under thefollowing conditions.

(Measuring Separation Factor of Acidic Gas Separation Module)

Condition 1; Raw material gas (flow rate: 2.2 L/min) having a ratio of“H₂:CO₂:H₂O=45:5:50” was supplied to respective carbon dioxideseparation modules as a supply gas at a temperature of 130° C. and at atotal pressure of 301.3 kPa and Ar gas (flow rate: 0.9 L/min) wasallowed to flow into the permeation side. The permeating gas wasanalyzed by gas chromatography and a CO₂/H₂ separation factor (α) wascalculated.

Condition 2; Raw material gas (flow rate: 1.72 L/min) having a ratio of“N₂:CO₂:H₂O=66:21:13” was supplied to respective carbon dioxideseparation modules as a supply gas at a temperature of 130° C. and at atotal pressure of 2001.3 kPa. The permeating gas was analyzed by gaschromatography and a CO₂/N₂ separation factor (α) was calculated.

(Measuring Separation Factor of Acidic Gas Separation FacilitatedTransport Film on Porous Support)

Condition 1; Raw material gas (flow rate: 0.32 L/min) having a ratio of“H₂:CO₂:H₂O=45:5:50” was supplied to respective carbon dioxideseparation films as a supply gas at a temperature of 130° C. and at atotal pressure of 301.3 kPa and Ar gas (flow rate: 0.04 L/min) wasallowed to flow into the permeation side. The permeating gas wasanalyzed by gas chromatography and a CO₂/H₂ separation factor (α) wascalculated.

Condition 2; Raw material gas (flow rate: 0.32 L/min) having a ratio of“N₂:CO₂:H₂O=66:21:13” was supplied to respective carbon dioxideseparation films as a supply gas at a temperature of 130° C. and at atotal pressure of 2001.3 kPa. The permeating gas was analyzed by gaschromatography and a CO₂/N₂ separation factor (α) was calculated.

The module factor was calculated based on the following equation relatedto Conditions 1 and 2.

Module factor=α of acidic gas separation module/α of acidic gasseparation facilitated transport film on porous support

TABLE 3 Module factor Condition 1 Condition 2 Example 1 0.56 0.39Example 2 0.43 0.31 Example 3 0.87 0.61 Example 4 0.62 0.49 Example 50.93 0.73 Example 6 0.79 0.55 Example 7 0.73 0.69 Comparative Example 10.11 0.04 Comparative Example 2 0.23 0.09

From Tables 2 and 3, it was confirmed that a higher module factor wasshown when the film protection unit was formed compared to ComparativeExample 1 in which the film protection unit was not formed. It isobvious that the module factor is increased and the separationperformance is improved when the impregnation rate of the adhesive inthe film protection unit is higher. While a module factor of 0.43 wasobtained under Condition 1 even when the impregnation rate of theadhesive of the film protection unit was 13% as in Example 2, the modulefactor was 0.23, which was low, when the impregnation rate of theadhesive in the film protection unit was 6% as in Comparative Example 2.From the results of Examples 1 to 3 and Condition 1 of ComparativeExample 2, it can be assumed that a module factor of approximately 0.3is obtained under Condition 1 when the impregnation rate isapproximately 10%. In addition, for the purpose of obtaining a modulefactor of 0.5 or greater under Condition 1, it is obvious that theimpregnation rate of the adhesive in the film protection unit ispreferably 25% or greater, more preferably 60% or greater, and stillmore preferably 80% or greater. In addition, the impregnation rate ofthe adhesive in the film protection unit in Example 1 is substantiallythe same as that of Example 4, but a higher module factor can beobtained when the film protection unit is formed on four sides as inExample 4, that is, the film protection unit is included in the foldedunit of the leaf. For this reason, it can be assumed that defects of theseparation film in the end portion of the supply gas channel member orin the folded unit can be prevented or gas inflow from defects can beprevented. In addition, in Examples of the present invention, a highmodule factor (0.3 or greater) was realized even in a case where greatstress was applied to a film as in Condition 2.

Even when the permeation rate of the film protection unit was high as inExample 5, the film protection unit functioned sufficiently well and ahigh module factor (0.3 or greater) was realized. The reason for thiscan be assumed that generation of defects caused by stress concentrationcan be suppressed even when a large amount of adhesive becomesimpregnated. Further, effects as the film protection unit can beexhibited without any problems even in a module in which the number ofleaves is higher as in Example 6. It is assumed that when the number ofleaves is higher, the module becomes larger, and thus film protectionperformance can be sufficiently exhibited even when a force for windingup is strong. The film protection unit effectively functions even in acase where an intermediate layer is provided in the acidic gasseparation laminate as in Example 7 and a high module factor is shown.The reason for this can be assumed that defects are not generated byintroducing the film protection unit and gas separation performance isexhibited even in a case where an intermediate layer used for improvingflat film performance is introduced.

Furthermore, in Conditions 1 and 2, it was confirmed that the modulefactor was extremely low in a case where a film protection unit was notincluded as in Comparative Example 1.

What is claimed is:
 1. An acidic gas separation laminate comprising: a composite film formed of a porous support which is formed by laminating a porous film and an auxiliary support film, a carrier which is disposed on the porous film side of the porous support and reacts with acidic gas in raw material gas, and an acidic gas separation facilitated transport film which contains a hydrophilic compound carrying the carrier; a permeating gas channel member which is laminated so as to face the auxiliary support film of the porous support and in which acidic gas permeated and passed through the composite film flows; and a film protection unit in which an adhesive becomes impregnated into the porous film at an impregnation rate of 10% or greater in a lamination direction of the porous support and an auxilliary impregnation rate of the adhesive in the auxiliary support film is smaller than the impregnation rate of the adhesive in the porous film.
 2. The acidic gas separation laminate according to claim 1, further comprising: a sealing unit which is formed by impregnating the porous film with the adhesive along the peripheral edge of the laminate at a porous film sealing unit impregnation rate of 60% or greater and formed by impregnating the auxiliary support film and the permeating gas channel member with the adhesive such that their respective impregnation rates become greater than or equal to the porous film sealing unit impregnation rate, wherein the film protection unit is formed in a state of being adjacent to the sealing unit.
 3. The acidic gas separation laminate according to claim 1, further comprising: a supply gas channel member which is disposed between the acidic gas separation facilitated transport film of the composite film that is obtained by inwardly folding the acidic gas separation facilitated transport film into two in the length direction, wherein a portion of the film protection unit overlaps a portion of the acidic gas separation facilitated transport film which contacts an end portion of the supply gas channel member.
 4. The acidic gas separation laminate according to claim 1, wherein the porous film is formed of a fluorine-based resin material.
 5. The acidic gas separation laminate according to claim 4, wherein the porous film is formed of polytetrafluoroethylene.
 6. The acidic gas separation laminate according to claim 1, wherein the adhesive is formed of an epoxy resin.
 7. The acidic gas separation laminate according to claim 1, further comprising an intermediate layer between the porous film and the acidic gas separation facilitated transport film.
 8. The acidic gas separation laminate according to claim 7, wherein the intermediate layer is a silicone resin layer.
 9. An acidic gas separation module comprising: a permeating gas collecting pipe; and the acidic gas separation laminate according to claim
 1. 10. The acidic gas separation module according to claim 9, which is a spiral type module.
 11. The acidic gas separation module according to claim 9, which is a flat film type module. 